Quitting smoking can improve lung health, but cutting down not enough — study

New United States research has found that quitting smoking can improve lung health, even in those were previously heavy smokers, but cutting down is not enough to preserve lung function.
Carried out by researchers at various universities across the United States, the study gathered data from 3,140 participants who were taking part in the Coronary Artery Risk Development in Young Adults (CARDIA) study.
The participants had an average age of 25 when they enrolled in the study, and data was collected over